Couple of metalworking questions.

[skipdiver]

Firstly, i need to cut a 5 or 6mm wide slot, about 75mm long in a piece of ali tube, which is 16g, or 1.6mm thick. Obviously a milling machine would do the trick but i don't have one, so is there another safe method to achieve this? Thinking it could be done with my router and a suitable bit or maybe in the drill press with a milling cutter somehow. Any pointers appreciated.

Secondly, i need to produce some small parts from stainless steel rod of 3mm and 4mm diameter. What's the best way to cut and finish the ends, which will need to be rounded over slightly, so they are not sharp. What grade is best to work and can i simply dress the ends on my bench grinder or will that be too rough?

Not worked with metals much in the past and am on a steep learning curve.

 

[Rorschach]

Drill each end of the slot in the drill press and then saw and file out the rest. If it's only a one off it won't be too much hassle.

 

[skipdiver]

Drill each end of the slot in the drill press and then saw and file out the rest. If it's only a one off it won't be too much hassle.

I need to do quite a few and quite regularly, so looking for something more efficient.

 

[AES]

You could make up a small jig (just wood/MDF, nothing too complicated) to hold both the tube and a Dremel-type tool fitted with a cut-off disc of the correct thickness - if you don't go for the modern "Click-Twist" type mandrel, but the old screw-type mandrel, cut off discs are available in various thicknesses (the modern type mandrel only holds the thinnest discs). At worst case you'd have to do the slots in 2 or 3 passes (in width) as I doubt Dremel anyway have cut-off discs quite so thick.

For the jig, have a look on here for a post by Dalboy in the Projects section, where he describes making a superb scale model of a WWII half track truck. There's a jig for doing the wheels fo that in his post and something a bit like that, though not so complex, would work well I think.

Also, if you go for a mains Dremel, I must say that I love mine - I've heard several moans about Dremel here, but I THINK they refer mostly to the new, battery models. Proxxon is another good buy I've heard (though here, they're more expensive than Dremel, hence me owning Dremel) Though from time to time, Aldi have a cheapo version on sale too. Clearly not so good as Dremel (my Aldi isn't any way, it runs very rough compared to the Dremel), but that would also do the job, and all the mandrels, etc, are interchangeable between makes if you use the chuck model, NOT the collet model.

For your SS rod pieces, I'm assuming you have no lathe? If not, then cut off to length as accurately as needed (32 TPI hack saw blade, or cut-off disc as above) then mount them in a rotating chuck (electric drill in bench holder, or better, in a drill press) then just use a smooth single cut file to smooth/round off the ends (see my bit on Files & Filing) - sorry, no self-promotion allowed!!

Seriously, you may mess up the first 1 or 2 SS rods, but you'll soon get the hang of it.

HTH

AES

 

[skipdiver]

Cheers AES, much food for thought there. I have a Dremel somewhere that i have never used and had forgotten about until you mentioned one, so that's do-able. Also have a drill press and lots of files i inherited when i bought my house and found them all in the shed. Apparently the guy who lived here before i bought the house made model boats and had lot's of gear which his family sold, but they left a box of bits under the bench containing the files. I will have a root through and see what's what.

 

[J-G]

I need to do quite a few and quite regularly, so looking for something more efficient.

That is the killer statement.

I've been watching both your threads and find some of the advice given to be seriously 'suspect'. Yes, I'm sure you could do the odd 'one-off' of all of the items you've mentioned by the methods suggested but I'm equally sure that you would very soon be dis-satisfied with both the quality of the items you produce and the time it takes. There is also a serious issue of safety if you use milling cutters in pillar drills - they are not designed for 'lateral' forces and the chance of the chuck detaching itself from the quill is very high - I speak from experience!!

Similarly, using a router free-hand - even guided with a jig - is akin to an accident waiting to happen. Although Ali dose need relatively high speed for best finish (on my mill I work at about 12-1500), routers are far too fast, generally starting at about 3k.

I still think that an investment in a small lathe is your best solution. No. it's not a milling machine but it is possible to do some milling operations on a lathe - just by thinking 'outside-the-box'. The work-piece doesn't have to be in the chuck/collet, it can be mounted on the cross-slide - with a suitable jig (which you would have to make of course) - and the cutter can be held in the chuck/collet. I did a great deal of milling work like this on my Myford 7 before I bought the Warco Mill.

The slot in your ali tube is the particular project I'm thinking of here - though you haven't said how long the tube is so I am making certain assumptions that it is short enough to be accommodated in your workshop. The Warco web-site doesn't specify the travel for the cross-slide but since the Osaki is a smaller spec and has 65mm, I suspect that you could anticipate the 70mm you would need to cut a 75mm long slot 5mm wide. It would be better to have a margin of error of course and is a question to ask of Warco.

As far as Stainless Steel is concerned, as long as the environment for the component is not 'Marine' then either 303 or 304 would be easier to machine than 316 but whether running them on a grinder would surfice is down to what sort of 'finish' you want. In a lathe with a collet chuck, you could very easily 'dome' or just chamfer the end of a bar, part off, do the next until the batch needed is complete then re-mount each for a second operation on the other end, producing a quality product.

 

[skipdiver]

Thanks again J-G. I do want to do things properly and safely. If that means buying a small lathe, then that is what i will do. I've spent my whole life working with wood and am always safety conscious when using machinery, but all things metal are a steep learning curve for me. I didn't take to metalwork at school and have steered clear of it since, as i have no interest in it. However, needs must now, so i will have to learn.

 

[AES]

J-G's quite right about a lathe of course, BUT unless you're making literally thousands off, bearing in mind your previous dislike of metal working, AND the budget (for even a simple set up reckon on double the cost of the machine itself - unless you get really lucky buying SH) I wonder if you're not approaching this in too complex a manner?

J-G's right about using a router (IMO - I don't like either the safety aspects or the high rpm), but without beating my own drum, I believe the set up I suggested with cut-off discs in a Dremel will do the job nicely if you make the jig accurately. And frankly, the idea of employing a lathe "just" to make nice domed ends on SS rod of 5 mm dia is sheer extravagance (financially) and overkill technically. Yes, of course a lathe will do a nice job on those rod ends (IF you have one), but you could soon learn to use a file and do without - IMO anyway, FWIW.

AES

 

[skipdiver]

Thanks again AES. That's the dilemma for me. Although not one off's , i only require about 20 or 30 pieces every few months. Maybe a hundred a year, if that.

I am in the market for a new pillar drill, so is there such a beast as a combined mill/drill that can be used for metalwork and woodwork?

 

[Rorschach]

You can indeed buy round column Mill/Drills and I think one would be very well suited to your job here.

 

[skipdiver]

Then that may be the way forward. Will have to do a bit more research.

Is the mention of a round column significant?

 

[Rorschach]

Yes, round column mills are much cheaper than knee/square column mills, they are also not as rigid. This limits the size of cutters and depth of cut they can take, that's why they are marketed as mill/drills. They are sold as heavy duty drills that can handle light duty milling. In practise however they are capable of good work if you take your time and work within their capacity, for instance using smaller cutters and taking multiple passes and using fly cutters instead of facemills etc. For the job you suggest that sounds like it falls right within the capacity of this kind of machine and the advantage also being that they are more portable and take up less space than a large knee mill.
If you might have use for a metal working lathe though, consider a small lathe with a milling attachment, simple slot work is very easy to do on a lathe and you will find that combination a lot more versatile than a mill, also taking up less space on the bench.

 

[skipdiver]

Thanks again and to everyone who has contributed. I now have a clearer understanding and will have a look around at my options. I have some time before i need to decide.

 

[AES]

+1 for rorsach's comments on a lathe with a simple milling attachment (I have no mill - "if ONLY SWMBO would allow me to stretch the "play toys" budget!!!). But a little milling attachment IS very handy - just as he says, PROVIDED you work within its limitations - especially rigidity.

But again, just a personal opinion, and not meaning to ramble on (again), for the relatively small quantities you mention, you'll honestly spend as much time - or even more - learning to use the lathe (and/or mill/attachment), as you will just learning to use basic hand tools with some simple little jigs.

I repeat myself ONLY because you say you don't like metal work (fair enough, no critical comment here) and I think that although a lathe (for example) is marvellous fun (if you're inclined that way), to learn to use it properly, even to make such "simple" items as domed ends, may well "drive you nuts" before you've got it.

Hand work (filing, etc) would also probably "drive you potty", but to do the small numbers you're talking about, it'll ultimately be quicker in learning curve, cheaper, and produce results which are just as satisfactory.

Right, that's more than my halfpenerth". Subject closed from me now.

But whatever you decide, good luck mate.

AES

 

[skipdiver]

There doesn't seem to be a lot out there in the round column mill/drill stakes.

 

[DTR]

I agree with the comments above. If you have no other interest in metalwork then buying a machine is probably not economical. If you have to buy a machine though, then a lathe with a milling attachment (or a custom jig) will make short work of it. A lathe is also a lot more versatile than a mill, even for a woodworker.

 

[skipdiver]

Thing is, i am in the market for a new pillar drill anyway, so if i can get one that takes care of my usual wood drilling needs and also has the benefits of a small mill, then that's the best of both worlds for me. I am currently paying someone to do the tasks i want to tackle, so buying some machinery to perform the tasks will quickly pay for itself. A drill/mill seems ideal to me.

One of my problems is limited space, so selling my pillar drill and replacing with a drill/mill won't upset my layout.

 

[DTR]

This is perhaps a moot point now given your last post, but I've just posed some photos of how it could be done on a lathe, as J-G, Rorschach and AES have suggested.

Milling cutter held in a morse taper collet in the headstock. Tube clamped to a milling attachment; the tee slot is a handy way of holding the tube a bit like a vee block. You could use a similar method with the tee slots on a milling machine table, and screw a stop block to the table to set the tube length. Note that the clamps were also home-made on the lathe:



Cheaper alternative using an angle plate and some packing to raise the tube up to the right height. The packing could be bolted to the angle plate so that it's permanently set when needed:



After taking the above photo I realised you could go a step easier and use a bog-standard toolmaker's clamp or G-clamp on the angle plate:

 

[MusicMan]

A couple on eBay might interest you. The Warco is pretty good:

http://www.ebay.co.uk/itm/Warco-Mill-Dr ... 0005.m1851

and the Arboga is superb:

http://www.ebay.co.uk/itm/AB-Arboga-U25 ... Sw4GVZ4RxS

With a mill drill the important thing to check is the rigidity of the alignment when the head is cranked up and down. The Arboga is excellent, not sure about the Warco. A trapezoidal column Warco is fine.

Keith

Keith

 

[J-G]

Thing is, i am in the market for a new pillar drill anyway

In that case look seriously at the Warco WM 12, 14 or 16 Mills depending upon your budget.
Not as versatile as a Lathe (You can 'Mill' on a Lathe but you can't 'Turn' on a Mill) but if the majority of the potential work is Milling and Drilling (rather than reducing Ali tube by 0.6mm !!) then these are ideal replacements. They can be fixed to your workbench and the 14/16 have floor-stands available.

They all come complete with a 13mm Jacobs chuck but no Collet Chuck. The issue about using a pillar drill for milling is mostly removed because even the Jacobs chuck is held in place with a draw-bar (so can't 'drop out') but I would still recommend buying an ER32 Collet chuck, I've found that much more stable for milling operations.

This would also remove all the concerns about having to buy a vertical slide or angle plate for a Lathe and mounting that on a cross-slide with limited travel - even the WM 12 has a 250mm travel and the others have 330mm. You will naturally need some work-holding equipment (Vice, Vee-Blocks, clamps etc.) but you may already have such which you use with your pillar drill.